Characterization of Asphalt Mixtures in Qatar

The State of Qatar went through a massive road construction program in the last decade as part of the ongoing development of its infrastructure and road transport network. Construction of roads in Qatar generally utilizes imported materials such as aggregate and binders as a result of the scarcity of local construction materials. Characteristics of asphalt mixtures are studied in this research program in order to evaluate mixtures properties in terms of aggregate packing, binder content, voids, mixture density, maximum density and Marshall Stability. Actual mixtures used in the Public Works Authority road projects were analyzed in the research program. Mixtures were prepared following the Qatar Construction Specifications (QCS, 2014). Combined aggregate gradations for different asphalt mixtures were compared with maximum density envelopes for different maximum aggregate sizes. Moreover, regression analysis was used to evaluate the strength of correlations established between different asphalt mixtures properties. The analysis of these mixtures is outlined in terms of general characteristics and consequently, recommendations are given to improve asphalt mixtures performance

Challenges for the Use of Local Materials in Unbound Road Subbase in Qatar

Current practice in Qatar is to blend local limestone with dune sand for use in unbound pavement applications. Dune sand is used to improve the properties of fine aggregate and compliance with the QCS 2014 requirements of plasticity and sand equivalent. The material has been successfully used for many years but currently facing the challenge of limited dune sand supply and recent government restrictions on its use in construction. The paper presents data on the properties of limestone obtained from different sources, tested in accordance with the QCS 2014 requirements. Variation of limestone source and the presence of clay particles greatly affected its suitability for use in unbound pavement applications. Improvement could be achieved by adjusting the grading of the material. Recommendations are made to revise the QCS 2014 specifications within the context of international specifications, when the unbound material is placed in a dry environment and away from the water level to enhance the wider utilization of local materials and sustainable construction in Qatar

Development and Performance of Cement Bound Materials in Road Pavements

The use of cement bound materials (CBMs) for road construction in Qatar is relatively new. CBM improves the structural capacity and durability of pavement, but considerations should be made to the setting time and strength development in hot arid environment, such as in Qatar. The paper presents a laboratory development and performance characteristics of CBM mixtures, with environmental and economic benefits through the use of local and recycled materials. The developed mixtures showed full compliance with the grading, strength and durability requirements of the Qatar Construction Specifications (QCS, 2014). Site data from Ashghal projects indicated the difficulty of producing consistent strength in practice, with the potential of increased strength and associated risk of reflection cracking in the asphalt overlaying. Recommendations are made to improve the construction practice and specification of cement and other hydraulically bound materials to enhance the service life of pavement and support the government strategy of sustainable construction

In vitro Activity of the Aqueous Extract of the Plant Kigelia africana Against Theileria lestoquardi

The objective of this study was to test the activity of the aqueous extract of the plant Kigelia africana against Theileria lestoquardi, the causative agent of malignant ovine theileriosis. Aqueous extract of K. africana fruits was screened for its in vitro activity against T. lestoquardi at different concentrations of 250, 500, 5000 and 10000 ppm. Lymphocytes infected with T. lestoquardi were isolated from heparinized blood with Ficoll-paque, grown in minimum essential medium and continuously sub cultured until passage 8 which was used for the test. The parasite was identified, using indirect fluorescent antibody test. The results revealed in vitro activities of 20%, 58% and 80% at concentrations of 500, 5000 and 10000 ppm, respectively. Lethal dose 50% and 99% (LC50 and LC99) were 2660.28 and 29980.34 ppm, respectively. The extract activity caused significantly (P≤0.05) high death of macroschizonts, decrease in the number of macroschizonts per cell, and increase in the number of extra cellular macroschizonts at concentrations of 5000 and 10000 ppm. The number of dividing cells significantly (P≤0.05) decreased at concentrations of 500, 5000 and 10000 ppm. The number of viable cells, also, significantly (P≤0.05) decreased at concentrations of 5000 and 10000 ppm compared with the control which did not significantly (P>0.05) increase. Besides, the activity of the highest concentration (10000 ppm) revealed some lymphoblast cells with degenerated nuclei. The study showed that K. africana has antitheilerial effect on T. lestoquardi and could be an effective candidate for the treatment of malignant ovine theileriosis after in vivo confirmation. Further studies are recommended for phytochemical analysis and mode of action

Effects of Introducing Different Levels of Groundnut Hay Treated with Urea and Molasses on Performance of Desert Lambs (Hammari Ecotype)

Non-traditional agricultural by-products are a potentially valuable alternative source of animal feed which may decrease dependence on traditional feed products and decrease overall feeding costs. This experiment was conducted to evaluate the effect of using groundnut hay in lambs fattening. Groundnut hay was used at three levels (0, 20 and 30%) in three iso-energetic and iso-nitrogenous diets (A, B and C). Twenty seven male lambs of Sudanese Desert sheep (Hamari ecotype) were selected according to their age (4-5months) and average live body weight (20.5Kg) and they were kept in Rural Development and Extension Center (R.D.E.C). The experimental feed includes three different levels of groundnut hay treated with urea and molasses (0, 20 and 30 %). Experimental animals were fed for 60 days included two weeks as adaptation periods. All the data was collected and statistically analyzed by using statistical package for Social Studies (SPSS version 17.0). an A Completely Randomized Design (CRD). One way analysis of variance (ANOVA) and Duncans multiple range were used to test for difference among the treatments means. The study showed a significant differences (P>0.05) among different treatments for average values of final live body weight gain(FLBWG), total live body weight gain(TLBWG), daily live body weight gain(DLBWG), feed conversion rate(FCR), feed conversion rate as % of live body weight gain, cost of one kg feed and cost of one kg live weight per (SG). While initial live body weight (ILBW) and daily feed intake (DFI) showed no significant differences (P>0.05) among different treatments. Treatment A (control) reported the highest and best values of final live body weight, daily weight gain, cost of one kg feed, and cost of one kg live weight followed by treatment B (%20) while treatment C (30%) reported the lowest values so, we recommend to use groundnut hay up to 20% for finishing desert lamb.&nbsp

Phytochemical, antimicrobial and cytotoxicity screening of ethanol extract of Acacia ehrenbergiana Hayne grown in Jazan Region of Saudi Arabia

Purpose: To explore the phytoconstituents of Acacia ehrenbergiana Hayne as well as its biological effects. Methods: Determination of phytoconstituents of ethanol extract of the plant was performed by gas chromatography-mass spectrometry (GC-MS) technique. Antibacterial screening was conducted against the isolates of Gram-positive and Gram-negative microbes while the anti-carcinogenic properties of the ethanol extract on cancerous cells were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cytotoxicity assay against breast MCF7, ovary cancer A2780 and colon cancer HT29 cells, respectively, in addition to normal MRC5 fibroblast cells. Results: GC-MS analysis identified 15 different phytochemicals in the ethanol extract. The extract exerted significant antimicrobial activity with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in the range 1.56 - 6.25 and 3.12 – 12.5 mg/L, respectively, against all test bacterial strains. Cytotoxic activity, obtained by MTT assay, was 28.81 ± 0.99, 12.50 ± 2.50, 23.90 ± 0.74 and 50.58 ± 3.24 μg/mL, against the three cancer cell lines and normal fibroblast, respectively. MTT cytotoxicity results was further confirmed by clonogenic survival assay on MCF7 cells. Conclusion: This study highlights the potential interesting ethnopharmacological applications of Acacia ehrenbergiana Hayne to treat drug-resistant pathogens as standardized extract. Keywords: Acacia ehrenbergiana, Phytochemistry, Antimicrobial, Cytotoxicit

Biopiracy <i>versus </i>one-world medicine – from colonial relicts to global collaborative concepts

Background: Practices of biopiracy to use genetic resources and indigenous knowledge by Western companies without benefit-sharing of those, who generated the traditional knowledge, can be understood as form of neocolonialism.Hypothesis: : The One-World Medicine concept attempts to merge the best of traditional medicine from developing countries and conventional Western medicine for the sake of patients around the globe.Study design: Based on literature searches in several databases, a concept paper has been written. Legislative initiatives of the United Nations culminated in the Nagoya protocol aim to protect traditional knowledge and regulate benefit-sharing with indigenous communities. The European community adopted the Nagoya protocol, and the corresponding regulations will be implemented into national legislation among the member states. Despite pleasing progress, infrastructural problems of the health care systems in developing countries still remain. Current approaches to secure primary health care offer only fragmentary solutions at best. Conventional medicine from industrialized countries cannot be afforded by the impoverished population in the Third World. Confronted with exploding costs, even health systems in Western countries are endangered to burst. Complementary and alternative medicine (CAM) is popular among the general public in industrialized countries, although the efficacy is not sufficiently proven according to the standards of evidence-based medicine. CAM is often available without prescription as over-the-counter products with non-calculated risks concerning erroneous self-medication and safety/toxicity issues. The concept of integrative medicine attempts to combine holistic CAM approaches with evidence-based principles of conventional medicine.Conclusion: To realize the concept of One-World Medicine, a number of standards have to be set to assure safety, efficacy and applicability of traditional medicine, e.g. sustainable production and quality control of herbal products, performance of placebo-controlled, double-blind, randomized clinical trials, phytovigilance, as well as education of health professionals and patients

Potential Molecular Mechanisms of Rare Anti-Tumor Immune Response by SARS-CoV-2 in Isolated Cases of Lymphomas

Recently, two cases of complete remission of classical Hodgkin lymphoma (cHL) and follicular lymphoma (FL) after SARS-CoV-2 infection were reported. However, the precise molecular mechanism of this rare event is yet to be understood. Here, we hypothesize a potential anti-tumor immune response of SARS-CoV-2 and based on a computational approach show that: (i) SARS-CoV-2 Spike-RBD may bind to the extracellular domains of CD15, CD27, CD45, and CD152 receptors of cHL or FL and may directly inhibit cell proliferation. (ii) Alternately, upon internalization after binding to these CD molecules, the SARS-CoV-2 membrane (M) protein and ORF3a may bind to gamma-tubulin complex component 3 (GCP3) at its tubulin gamma-1 chain (TUBG1) binding site. (iii) The M protein may also interact with TUBG1, blocking its binding to GCP3. (iv) Both the M and ORF3a proteins may render the GCP2-GCP3 lateral binding where the M protein possibly interacts with GCP2 at its GCP3 binding site and the ORF3a protein to GCP3 at its GCP2 interacting residues. (v) Interactions of the M and ORF3a proteins with these gamma-tubulin ring complex components potentially block the initial process of microtubule nucleation, leading to cell-cycle arrest and apoptosis. (vi) The Spike-RBD may also interact with and block PD-1 signaling similar to pembrolizumab and nivolumab- like monoclonal antibodies and may induce B-cell apoptosis and remission. (vii) Finally, the TRADD interacting “PVQLSY” motif of Epstein-Barr virus LMP-1, that is responsible for NF-kB mediated oncogenesis, potentially interacts with SARS-CoV-2 M(pro), NSP7, NSP10, and spike (S) proteins, and may inhibit the LMP-1 mediated cell proliferation. Taken together, our results suggest a possible therapeutic potential of SARS-CoV-2 in lymphoproliferative disorders